Cloth-cutting machine



- Dec. 15, 1942.

w. BANGSER CLOTH-CUTTING MACHINE Filed. Oct... 16, 1941 2 Sheets-Sheet 1 INVENTOR WILL/AM 519N619 ER ATTORNEYj Dec. 15, 1942. w, BANGSE'R 2,305,465

CLOTH-CUTTING MACHINE Filed Unit. 16, 1941 2 Sheets-Sheet 2 INVENTOR W/Ll/AM BAA/65f)? ATTORNEYS Patented Dec. 15, 1942 U N l TE D STAT PAT E N T' O FF l C E CLOTH-CUTTING MACHINE Wi liam fi n s r, Ne York, N assi o to H- Maimin Company, Incorporated, New York, N. Y., a corporation of NewYork Application October 16, 1941, Serial No. 415,269

6' Claims.

This invention--relates to improvements in cloth-cutting machines of the reciprocating knife type and has to do particularly with means for mounting the knife on the reciprocating cross-- head of the machine;

The knives used in cloth-cutting machines of this type are subjected to severe usage, must be constantly sharpened and soon wear out. They must, therefore, be frequently removed and replaced. Thelower end of the reciprocating crosshead is provided with a depending knife support through which a locking bolt extends. The upper end of the knife is provided with a vertical slot for straddling the bolt so that the knife, when in place, is clamped between the knife support and the nut on the locking bolt. During cutting operations the resistance of the cloth to the passage of the machine tends to force the knife back against the standard, which causes the standard to wear. Now the operator, when mounting a new blade in the machine, must adjust it so that the blade bears against the bottom of the slot in the standard, and so, in a given machine, as the standard wears, a proper adjustment of new blades requires that they be moved back gradually more and more relative to the cross-head. Thus, the knife bolt slot at the upper end of the blade must be made wide enough to permit this lateral adjustment in the plane of the blade and the slot cannot, therefore, be narrow enough to hug the cross-head. This being so, the blade is held in position merely by the pressure exerted upon it by the locking bolt nut and the knife support, and as all of these have hardened surfaces it is impossible to get a satisfactory locking action.

--Although the pressure of the cloth forces the knife back against the standard during the cutting operation, the sharpening rollers, which mustcontinually be brought to bear against the knife edge, have a tendency to move the knife away from the standard. There is, of course, no question of cloth pressure counteracting the roller'pressure-because the knife is not in contact with the cloth when it is being sharpened. Thus, each grinding operation tends to swing the knife slightly forward about the locking bolt as a pivot.- As a result, the lower cutting edge of the knife may strike against the throat plate, which will not only dull the knife and impair its cutting efficiency, but most likely break it. And a knife breaking under these circumstances, is a dangerous thing for the operator. Another disadvantage flowing from the present unsatisfactory method-of clamping the bolt'to the knife support, is the possibility that the'locking bolt nut may become loose and-pennit-moveme'nt of the cross-head away from the knife; Qnce this happens, breakage or the knife is inevitable, 'because the rapidly reciprocating cross-head will deliver'liammer blows to'the upper end of the loosened knife. A still further disadvantage arises from the fact that'a careless operator may set the knife too low, the first downward stroke of the cross-head sending the knife into the table, and this, if'it' does'not" break the knife, will certainly dull'it,

- In accordance with the presentinvention I have provided means for locking the knife-on the knife support of the cross-head so firmly that it cannot be swung forward by the grindstones, and cannot carelessly be set too low, yet can be adjustedto compensate for wear in the standard; I have accomplished this object by providing a horizontal key on the cross-head and a cooperating horizontal key slot on the knife, the key slot being sufliciently longer than the key to permit of adjustments in the plane of the blade. One specific embodiment of my invention,

which I have found satisfactory in' practice, in-

volves the use of a separate locking plate equipped with the key, this plate lying between the knife and the locking bolt nut, The upper end of this plate is provided with a pair of prongs which straddle the lower end of the cross-head and may be bent to clamp it permanently. This p'ronge'd extension of the plate; making itssnug contact with the cross-head; prevents any pivoting of the knife about the locking bolt during grinding. At the same time the knife bolt-slot may be' made sufficiently wide,- as at present, to permit of necessary adjustments in the plane of the blade. The key having a fixed position relativeto the cross head, the vertical setting of the knife is effected automatically. The operator merely thrusts the new knife upwardly between the knife support and the locking plate until he feels the'key snap into the key slot, whereupon the nutis tightened and. the knife automatically drawn into correct alinement. Even though the locking bolt nut may become loosethe knife cannot leave the cross-head nor swing about the locking bolt until the nut has made several turns,

v, and this is not likely to happen.

Inthe accompanying drawings I have illustrated certain preferred embodiments of my invention. In these drawings Figure 1 is a front elevation, partly in section, of a cloth-cutting machine of-the reciprocating knife type in'which thekn'i'f isrnk'n'ir'iiiebl-"o'r'rthe cross-head in accord:

head 6.

ance with the present invention; Figure 2 is a section taken along line 2-4 of Figure 1; Figure 3 is a side elevation of a knife embodying the novel features of the present invention; Figure 4 is a detail on an enlarged scale showing how the locking plate functions to hold the blade in proper position on the cross-head; Figure 5 is a section taken along line 5-5 of Figure 4, showing the relationship between the parts before the locking bolt nut is tightened to draw the key home and into the key slot; Figure 6 is a view similar to Figure 5 showing the relation between the parts when the locking bolt has been tightened and the blade is in operative position; Figure 7 is an elevation of one form of locking plate; Figure 8 is a side or edge view of the plate in Figure 7; Figure 9 is a plan view of a modified form of locking plate; Figure 10 is a side or edge view of the locking plate shown in Figure 9, and Figure 11 is an edge view of a still further modi fied form of locking plate.

The cloth cutting machine illustrated in Figures 1 and 2 comprises the usual base I on which is mounted a standard 2, carrying a motor in a motor-housing 3. A knife 4 is mounted for reciprocation in a vertical slot 5 in the forward edge of the standard. The reciprocating mechanism 'comprises generally a cross-head 6 slidable in gibs l, a connecting rod 8 and a crank, not shown, mounted on the flywheel of the motor. The presser foot, guard, and grindstones are not illustrated..-

The foregoing all constitutes standard construction, and, of itself, forms no part of the invention.

Depending from the lower end of the cross-head 6 is a knife support 9 through which passes a knife bolt l0 having a flattened shank and provided with a nut ll. Between the knife support 9 and the nut II I have placed a locking plate l3 provided with a central opening M for the bolt 10 and a fork l5 embracing the lower end of the cross- The locking plate is provided with a key l6 extending horizontally on both sides of the opening I4. In order to ensure that the locking plate shall hug the cross-head snugly and have no swinging movement relative to the cross-head in the plane of the knife'support, I may bend in the upper ends I] of the prongs of the fork 15 to embrace thecross-head, as shown in Figure 4. This does not, however, prevent movement of the looking plate toward and away from the knife support to accommodate the knife.

The knife is provided at its upper end with a slot [8 designed to receive the shank of the bolt Iil atit's lower end, the lower end of the crosshead lying within the mouth of the slot, as shown best in Figure 2. A horizontal key slot 19 extends transversely of the slot I8 near its lower end. The width of this key slot is slightly less than that of key It so that the key, with its chamfered edges may be snugly seated in the slot. The slot is, however, longer than the key to permit of transverse adjustment in the plane of the knife blade. The slot [8, being wider at the top than at the bottom, is sufficiently wide to permit of this transverse adjustment with relation both to the bolt [0 and the lower end of the cross-head 6.

The modified for-ms of locking plate, shown in Figures 9, 10 and 11, differ from the form shown in Figure '7 only in the substitution of a single prong 20 having a tail 2|, bent over as shown, in place of the fork IS with its two prongs. The tail 2| is intended to pass through a properly proportioned slot in the blade support with which it makes a snug engagement and thus prevent movement in a plane parallel to the face of the support, as in the case of the plate shown in Figure '7. In Figure 11, a stud 22 is mounted on the upper end of the plate and fits within a hole in the blade support, performing the same function as the tail 2| shown in Figure 10.

To mount a knife on the machine illustrated, the nut II is loosened and the upper slotted end of the knife inserted between the blade support and the locking plate by an upward movement, slot I8 straddling'the shank of the bolt I0 and the lower end of the cross-head 6. When the key slot l9 reaches the key IS in the locking plate, the key tends to move into the slot, or will if the nut II has not been loosened too much. In any event the operator will have no difficulty in determining when the key and slot are in engagement. The vertical position of the knife is thus accurately fixed. Before tightening the nut I I, the operator moves the knife back against the bottom of the slot 5 in the standard and thus makes the proper transverse adjustment of the knife. The nut II is then tightened so that the knife is firmly clamped between the knife support and the looking plate, and the machine is ready for use.

The interlock between the key 15 and the slot It makes it impossible for the grindstones to swing the knife about the bolt H] as a pivot. This interlock makes the knife and locking plate a unitary structure, in effect, and the locking plate is clamped to the cross-head in such a way that movement in a plane parallel to that of the knife blade is impossible. At the same time horizontal adjustment of the knife in the plane of the blade can easily be effected before the nut i I is tightened. Another advantage flowing from my novel construction is that a slight loosening of the nut H will not result in disconnecting the knife from the cross-head. Before this would be possiblethe nut l I would have to travel away from the blade support a distance greater than thickness of th key'l6. In practice this would rarely 7 ever happen.

I claim: V

1. In a cloth-cutting machine of the reciprocating knife type, the combination of a crosshead, a knife, cooperating horizontal key and key slot on the cross-head and knife, the slot being longer than the key to facilitate transverse adjustment of the knife in the plane thereof, and means for clamping the knife to thecross-head.

2. In a cloth-cutting machine of the reciprocating knife type, the combination of a crosshead, a knife, a horizontal key on the cross head, a cooperating key slot in the knife longer than the key to facilitate transverse adjustment of the knife in the plane thereof, and a nut and bolt for clamping the blade to the cross-head.

3. In a cloth-cutting machine of the reciprocating knife type, the combination of a crosshead, a knife support on the cross-head, a locking plate having a horizontal key facing the knife support, a bolt passing through the knife support and locking plate, a knife, the upper end of which lies between the knife support and the locking plate, a vertical slot in the upper end of tlre knife straddling the lower end of the crosshead and the bolt, and wider than either, a key slot in the knife of slightly less width than the key but longer than the key, and a nut to clamp the knife support, knife and locking plate together with the key and key slot in engagement.

4. In a clotch-cutting machine of the reciprocating knife type, the combination of a crosshead, a knife support on the cross-head, a locking plate having a horizontal key. means for mounting the locking plate on the cross-head so as to be movable toward and away from the blade support but not movable in a plane parallel to the blade support, a knife, the upper end of which lies adjacent the locking plate, a key slot in the knife of slightly less width than the key but longer than the key, and means for clamping the knife support, knife, and locking plate together With the key and key slot in engagement.

5. In a cloth-cutting machine of the reciprocating knife type, the combination of a crosshead, a knife support on the cross-head, a looking plate having a horizontal key facing the knife support, means for mounting the locking plate on the cross-head so as to be movable toward and away from the blade support but not movable in a plane parallel to the blade support,

a bolt passing through the knife support and locking plate, a knife, the upper end of which lies between the knife support and the locking plate, a vertical slot in the upper end of the knife straddling the lower end of the cross-head and the bolt, and wider than either, a key slot in the knife of slightly less width than the key but longer than the key, and a nut mounted on the bolt to clamp the knife support, knife and looking plate together with the key and key slot in engagement.

6. A knife for a reciprocating knife cloth-cutting machine having a longitudinal slot at its upper end, wider at its mouth than at its base, and a transverse key slot crossing the longitudinal slot near its base.

WILLIAM BANGSER. 

